Proces for the hardening of compositions of nickel and copper.



. the proportions I molten; then stir it welL.

an earn PATENT amen JOHN ARGHIBALD DOUGLASS, OF DARTMOUTH, NOVA SOOTIA, CANADA.

PROCESS FOR THE HARDENING OF COMPOSITIONS OF NICKEL AND COPPER.

No Drawing.

To all whom it may concern:

Be it known that I, PETER JoHN ARCHI- BALD DOUGLASS, of the town of Dartmouth, in the county of Halifax, Province of Nova Scotia, Dominion of Canada, have invented certain new and useful Improvements in Processes for the Hardening of Compositions of Nickel and Copper, of which the following is the specification. This invention relates to alloys of the nickel-copper group, and the objects of the lnvention are to produce an alloy of this class that is sufiiciently hard and at the same time tough and supple, to be useful in the manufacture of edged tools, and generally to replace steel in such cases as require metal 7 parts capable of maintaining a cutting edge without being liable to corrosion by moisture, or even salt water.

The invention consists essentially of an alloy of substantially twoparts of nickel and one part of copper, having small quantities of ferro-silicon and chromium added and incorporated. Thee quantities l[ ,have found to produce the most successful results are as follows: Sixty-seven parts (by weight) of nickel, thirty-three parts (by weight) of copper, five to fifteen parts (by weight) of ferro-silicon, two to eight parts by weight of chromium. Ferro silicon may be easily obtained as a commercial article and of silicon in it is from 45 to 55%.

In the preparation of the alloy, the .following method of procedure has been found to yield the best results: Place the copper and nickel in a covered crucible, preferably of graphite, and heat until all the metal is Next add the ferro-siliconto the molten metal in the crucible, and again stir well, to thoroughly incorporate the added element. Next add the chromium, and stir well until it is properly molten and incorporated with the-other contents of the crucible. The contents of the crucible should now be poured into cold water; and again heated till molten, when they may be cast in molds in the usual manner. It has been found in practice that a.

Specification of Letters Patent.

Patented Dec. Mi, 11915.

Application fil ed February 9, 1914. Serial No. 817,529.

preferable to harden them further, by heat-' ing them to a dull red, and plunging them in water, after the tool is in its finished shape. If a knife or thin piece of the applicants metal is heated it will assume different colors e. g. straw, blue, purple, etc., as in steel, and if dipped in cold water a further hardening effect occurs. In the preparation of this alloy, any of the well-known fluxes at present on the market may be used at any or all of the stages of the preparation for the purpose of keeping the metal clean and free from dirt, oxid, or the like in suspen sion in the metal.

The alloy is especially useful for knives of all kinds and for all purposes, and the low cost (knives may be made from this metal not greatly exceeding the cost of steel knives) has made it applicable in many cases where considerable inconvenience has been experienced by corrosion of other metals. The appearance of the alloy is very similar to that of silver, and a fine polish is easily imparted to it.

As many changes might be made in the above proportions and in the process of manufacture, such changes being within the spirit and scope of the following claim, it is intended that all matter contained in the.

accompanyingspecification shall be interpreted as illustrativeand not in a limiting stated, namely, nickel-67 parts by weight;

copper33 parts by Weight; 10 parts by weight of ferro-silicon, 2 parts by weight of chromium.

In witness whereof I have hereunto set 'my hand in the presence of two witnesses.

' PETER JOHN AROHIBALD DOUGLASS.

Witnessesz. C. E. AoLIoNBY C. W. FIDEN. 

